Honda Melody Deluxe II engine help please!

[KeithyM]

Hi Guys

I'm new to this so please bear with me!

In an attempt to relive the fun I had when I was a youth (and to cut down on the costs of commuting these days too!) I have purchased a 1 owner from new Honda Melody Deluxe II in the glorious dayglo yellow colour. But I have a problem that with my very limited technical knowledge I cannot solve...

The ped fires up from either the electric starter or on the kick first time, every time and then ticks over very sweetly if left. It produces the right amount of smoke to show that the oil pump system is working. I have fitted a new spark plug and cap. The issue is this, when I set off I can run at full throttle/rpm for about 10 minutes with the ped easily and smoothly hitting 30/35 mph with no bother but any longer the engine will die if I go anywhere near fully opening the throttle. This means that I have to complete my journey at 5-10mph tops and no more, along with stopping every 10 feet to let the engine 'rest' before pulling off again.

Is this a cooling issue with the engine getting too hot, or is there a blockage somewhere. I think it may be the former as the engine seems to perform optimally when cold.

I have no technical knowledge just a love for my old ped, so any help from any direction will be very gratefully received.

Thanks in advance!

[Busa1340R]

Blocked fuel tank breather maybe?

Or maybe a split vac pipe to the fuel tap?

Or maybe a sticking carb float valve?
____________________
Current: 2010 Suzuki GSX1340R Hayabusa, 2013 Yamaha YP250R X-Max Sport - Previous: Triumph Sprint ST1050ABS, Honda XL600V Transalp, Honda NT650V Dullsville (don't ask!), Kawasaki ZX9R E1, Honda NX650 Dominator, Suzuki GSX1300RKZ Hayabusa, Honda CBR1000FM, Kawasaki GPZ500S, etc etc

[Matt B]

When you say let it rest, what do you mean exactly?

Does it die completely or just lack power but still manage to tick over? If it was overheating and seizing I would expect it to die totally.
____________________
stinkwheel: He had an animated .gif of a cat performing fellatio. It's not socially acceptable. It can have real life adverse effects on other people.

[KeithyM]

Thanks guys.

If I continue at full throttle she will slow and die but will restart first time. If I reduce speed and pull over to a stop she will regain tick over without dying but I then need to wait a minute before pulling off otherwise she will die when I open the throttle. Once this process has happened once she never reaches full speed with an open throttle and continues to want to die every few feet thereafter. Even the slightest incline sees me pushing her up it. I've also noticed a bit over over run when I switch of the engine with the key although this 'putting' only lasts for 5-10 seconds.

Thanks again!

[Nobby the Bastard]

Definately sounds like it's running out of fuel. Do these have a vaccuum controlled tap or is it just a gravity feed to the carb?

Anyway, try taking off/ open the petrol cap and then riding it. If the issue goes away, the air breather in the cap is blocked.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Matt B]

Yup, either way it sounds like fuel starvation.

Was it stood for a long time before you got it? Things may have dried out and got gunked up.
____________________
stinkwheel: He had an animated .gif of a cat performing fellatio. It's not socially acceptable. It can have real life adverse effects on other people.

[stevo as b4]

Can you try manually operating the choke when or before riding? if it's not fuel starvation from a blocked tank breather, dirty fuel tap, line or filter and the carb is clean and float height correctly set, then it could be running lean at full throttle?

It would be worth de-carbonising the engine top end and filling the exhaust system with caustic soda solution and then hanging it up for 24hours to clean it all out. If it's been run on lawnmower grade oil for years, it could have easily become blocked up with carbon deposits in the combustion chamber, piston crown and exhaust port/system.

Low performance 2strokes are often worse for getting all carbon deposits building up over time, and this could be causing your overheating and or pre-ignition when hot.

[KeithyM]

Thanks again guys.

I'll try riding her home from work with the fuel cap off and see if that makes a difference.

I bought the ped from an old lady who's owned it from new and turned it over every day even when not used. It's only covered 7,000 miles since 1985 and has flown through all MOT's so it's been well looked after and maintained. It's always been run on good oil and good quality fuel too.

I'm not technically minded at all but I do have a Haynes book at home so provided I get home in one piece (I have to traverse a very busy dual carriageway for a mile or two which I don't fancy suddenly losing power in the middle of!) I'll try and get my head around all of your suggestions. As I have no garage or workshop I'm limited to roadside repairs too.

If I can't sort her myself does anyone know of a reasonably priced mechanic in the Bristol area, it's my only mode of transport and I need her to get me to work too.

Thanks again all

[CaNsA]

[KeithyM]

Well I tried the trip home with no fuel cap and there was an improvement but only slight.

I managed to get home with the engine dying only once but I still couldn't get over 10-15mph and a fully open throttle made the engine misfire and 'lumpy', certainly nowhere near as smooth as with the cap on. I think I even heard a misfire.

I'm even more confused.

Thanks again guys

[KeithyM]

Well I tried the trip home with no fuel cap and there was an improvement but only slight.

I managed to get home with the engine dying only once but I still couldn't get over 10-15mph and a fully open throttle made the engine misfire and 'lumpy', certainly nowhere near as smooth as with the cap on. I think I even heard a misfire.

I'm even more confused.

Thanks again guys

[bypass2]

maybe a faulty fuel sender

[Matt B]

Get the carb and the associated fuel gubbins off, strip and clean the lot with some carb cleaner. Try again.
____________________
stinkwheel: He had an animated .gif of a cat performing fellatio. It's not socially acceptable. It can have real life adverse effects on other people.

[map]